With the improvement of living standards, demands on display products change rapidly. Future display devices will develop to be lighter and thinner, and with higher luminance, lower power consumption and higher quality.
At present, to make a display product lighter and thinner, the main solution is to continuously reduce the thickness of a backlight module. The thickness of the backlight module is reduced mainly by reducing the thicknesses of respective film materials in the backlight module, such as a backplate, a diffuser plate and an optical film layer in the backlight module, by reducing the thickness of a system housing for packaging the backlight module, and the like. In addition, to reduce the thickness of the backlight module, the backlight module generally adopts an edge-type light source, that is, light emitted from the light source enters from one side of the backplate, and most of incident light enters into the diffuser plate from one side thereof. The diffuser plate can diffuse incident light, so that light passing through the diffuser plate becomes more uniform.
To reduce the thickness of the system housing, unnecessary metal or nonmetal material of some parts in the system housing can be generally removed, so that the thickness of the system housing becomes non-uniform, and this may directly result in non-uniform heat conduction of the backlight module packaged inside the housing, that is, local temperature inside the backlight module is high, and in addition, thicknesses of respective film layers in the backlight module become thinner and thinner, which readily cause a film layer with a smaller thickness in the backlight module to wrinkle, thus seriously affecting the display quality of the display product.
Further, as the thickness of the diffuser plate in the backlight module is reduced, the specification and dimension of the light source is accordingly reduced, and this causes both light extraction amount of the light source and transmission efficiency of the diffuser plate to be reduced, so that the backlight brightness of the backlight module is limited, resulting in that the luminance of an ultrathin display product is generally low.